Generating Energy from Sewage Sludge

Sewage sludge is treated to make it safe for agricultural application. Treated sewage sludge produces nutrient-rich biosolids, which are principally used as soil fertilizer. Biosolids and the dried untreated form of sewage sludge are also used as alternative fuels. They are usually co-fired with other fuels like coal, municipal solid waste, wood waste, and agricultural waste. Not all sewage sludge, however, can be incinerated to produce energy. The water content and high levels of inert materials in sludge make its net fuel value relatively low.